In the sentence, "You may be wrong, but you may be right." May mean:a. abilityb. permissionc. possibility

In which of the statements does "must" express necessity?a. There's somebody in the other office. It must be my boss!b. You mustn't smoke here!c. I must go right now!

In which of the sentences can "since" be replaced by because?a. I have enjoyed science since I was a child,b. I am interested in this article since I like science,c. I've been studying science since 1988.

Choose the alternative in which "while" is being used to express a contrast.a. While the machines are working, let's have some coffee.b. I usually take a shower while my mom is preparing breakfast.c. My dad is a dreamer, while my mom is too realistic.

Choose the correct statement.a. Many people have computer phobia, that generates more unemployment.b. Many people have computer phobia, which generates more unemployment.c. Many people have computer phobia, what generates more unemployment.